Must exclude cutaneous involvement in multiple myeloma and plasmacytoid B-cell lymphomas, such as primary cutaneous extranodal marginal zone lymphoma Etiology/Pathogenesis • Cell of origin is immunoglobulin-secreting, heavy-chain class-switched, terminally differentiated B…
Different clinical features: Multiple cutaneous lesions, may have joint &/or internal organ involvement in multicentric cutaneous reticulohistiocytosis • Juvenile xanthogranuloma • Langerhans cell histiocytosis • Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy) Solitary…
Diffuse growth pattern, not scattered cells of lymphomatoid granulomatosis (LYG) Not angiocentric, usually no necrosis, and no mixed background infiltrate • Vasculitis Can show similar histologic features to LYG with inflammation…
Xanthelasma, eruptive, tuberous, tendinous, planar, plexiform Etiology/Pathogenesis • Associated with hereditary lipoproteinemias and occasionally secondary lipoproteinemias • May also occur in normolipemic patients Particularly plexiform xanthoma Clinical Issues • Wide age range (children…
May be difficult to identify, especially if desmoplastic type or heavily inflamed Papular Growth in Pigmented PatchThe marked area , prior to biopsy, shows a papular growth in an ill-defined…
Usually on extremities • Angiokeratoma of Fordyce Elderly men Multiple lesions, often on scrotum • Angiokeratoma of Mibelli Childhood Warty lesions over bony prominences of acral locations • Angiokeratoma corporis diffusum Associated with…
Pretibial skin also common Uncommon on face • Benign but up to 50% recur • Rare intraoral, orbital, intradural, and paraspinal cases Microscopic • Multiple lobules with abundant myxoid matrix • Well-defined lobular architecture…
Associated with low recurrence and metastatic rates Microscopic • Multinodular solid or cystic tumor based in dermis • Solid areas composed of dense collections of cells with focal ductal lumina • Cystic/glandular areas…
Localized, wart-like variants, solitary or multiple • Nevus unius lateris Long, linear lesions on unilateral extremities • Ichthyosis hystrix Large, bilateral lesions on trunk Etiology/Pathogenesis • Epidermal nevus syndrome includes neurological, ocular, and…
Juvenile XanthogranulomaThis is a typical appearance of a juvenile xanthogranuloma removed from the face of a small boy. The lesion is uniform and cellular and proliferates in the dermis with…
